In terms of ACDC, I wouldn't say the bass players/drummers were key members - certainly the Youngs didn't see them that way: they had to play exactly what they wanted with none of their own flair. Cliff Williams was told what to play, where to stand on stage that he had to walk forward for the BV's and walk back without turning round (apparently Brian Johnson bollocked by Malcolm during his first gig cos he was talking too much between songs) Still, better than Mark Evans, who didn't play on much of the records because the band didn't think he was good enough, and George Young played.